Potato water use and yield under furrow irrigation

Field experiments were conducted to study the effects of plant-furrow treatments and levels of irrigation on potato (Solanum tuberosum L.) water use, yield, and water-use efficiency. The experiments were carried out under deficit irrigation conditions in a sandy loam soil of eastern India in the winter seasons of 1991/92, 1992/93, and 1993/94. Two plant-furrow treatments and two levels of irrigation were considered. The two plant-furrow treatments were F₁ - furrows with single row of planting in each ridge with 45 cm distance between adjacent ridges, and F₂ - furrows with double rows of planting spaced 30 cm apart in each ridge with 60 cm distance between adjacent ridges. The two levels of irrigation (LOI) were I₁ - 0.9 IW/CPE and I₂ - 1.2 IW/CPE, where IW is irrigation water of 5 cm and CPE is cumulative pan evaporation. Treatment F₂ produced highest tuber yield in all years with average value of 10,610 kg ha ^-1 and 12,780 kg ha ^-1 at LOI of I₁ and I₂, respectively. On average, six irrigations with a total of 25 cm, and seven irrigations with a total of 30 cm were required for both treatments F₁ and F₂ at LOI of I₁ and I₂, respectively. Treatment F₂ resulted in a significantly higher number of branches and tubers per plant, foliage coverage and water-use efficiency for both irrigation levels than treatment F₁. Average daily crop evapotranspiration was found to range from 1.1 to 3.4 mm and from 1.2 to 3.9 mm for treatment F₁ and from 1.1 to 3.6 mm and from 1.2 to 4.0 mm for treatment F₂ at LOI of I₁ and I₂, respectively.     

Response of strawberry to organic versus inorganic fertilizers

The aim of this research was designed in order to optimize integrated plant nutrient supply (IPNS) through balanced fertilization of organic, inorganic and microbial inoculants in strawberry cv. Chandler. The potential efficiency of bio-organics used along with chemical fertilizers on cropping behaviour, physical-chemical and biological properties of rhizosphere soil, fruit yield, quality attributes and leaf nutrient content was investigated. The significant improvement in physico-chemical properties of the soil and nutrient uptake was recorded. The uninoculated control received farmyard manure (FYM) and inorganic nitrogen (N) recorded the highest cation exchange capacity (CEC) and soil organic carbon (OC) content. Highest available N and phosphorus (P) of soil were recorded in vermicompost and inorganic N applied in two and one split, respectively. The concentration of micronutrients cations viz., iron (Fe), zinc (Zn), manganese (Mn) in soil was higher in treatment received vermicompost and inorganic N in two splits. The integration of bio-organic nutrient supplements also significantly enriched the microbial status of the rhizosphere soil, leaf nutrient concentration and maintained soil health and productivity on long term basis for sustainable fruit production.     

Hydrus-1D model for simulating water flow through paddy soils under alternate wetting and drying irrigation practice

Paddy and Water Environment - Alternate wetting and drying (AWD) irrigation practice in paddy cultivation requires a safe soil moisture stress level in the root zone for which irrigation water...     

Treatment of wheat straw using tannase and white-rot fungus to improve feed utilization by ruminants

Background

Current research to enrich cattle feed has primarily focused on treatment using white rot fungi, while there are scarce reports using the enzyme tannase, which is discussed only in reviews or in the form of a hypothesis. In this context, the aim of the present study was to evaluate the effect of tannase on wheat straw (WS) and also the effect of lyophilized tannase at concentrations of 0.1%, 0.2%, and 0.3% (w/w) on WS followed by fermentation with Ganoderma sp. for 10 d and compared in relation to biochemical parameters, crude protein (CP) content, and nutritional value by calculating the C/N ratio in order to improve the nutritional value of cattle feed.

Results

Penicillium charlesii, a tannase-producing microorganism, produced 61.4 IU/mL of tannase in 54 h when 2% (w/v) tannic acid (TA) was initially used as a substrate in medium containing (% w/v) sucrose (1.0), NaNO₃ (1.0), and MgSO₄ (0.08 pH, 5.0) in a 300-L fermentor (working volume 220 L), and concomitantly fed with 1.0% (w/v) TA after 24 h. The yield of partially purified and lyophilized tannase was 5.8 IU/mg. The tannin-free myco-straw at 0.1% (w/w) tannase showed 37.8% (w/w) lignin degradation with only a 20.4% (w/w) decrease in cellulose content and the in vitro feed digestibility was 32.2%. An increase in CP content (up to 1.28-fold) along with a lower C/N ratio of 25.0%, as compared to myco-straw, was obtained.

Conclusions

The use of tannin-free myco-straw has potential to improve the nutritional content of cattle feed. This biological treatment process was safe, eco-friendly, easy to perform, and was less expensive as compared to other treatment methods.     

Screening and selecting novel AM fungi and Azotobacter strain for inoculating apple under soil solarization and chemical disinfestation with mulch practices for sustainable nursery management

The objective of this study is to investigate the response of screening, and selection of novel indigenous AM fungal species and Azotobacter chroococcum strains for inoculating apple under different soil disinfestations and moisture conservation mulch practices for sustainable nursery management. Two local AM fungal species namely, Glomus fasciculatum (Thaxter sensu Gerdemann) and Glomus mosseae (Nicol. & Gerd.), and two strains of A. chroococcum viz., A. chroococcum strain-I (AZ₁) and A. chroococcum strain-II (AZ₂) were inoculated at nursery stage under soil solarization, chemical disinfestation and natural soil conditions at four different mulch materials namely, black plastic mulch (BPM), and organic mulches, i.e. grass mulch (GM); cover crops (CC); green manuring + clean cultivation (Gm + Cc). The comparative performance of the seedlings on the impact of local AM species and A. chroococcum strains on growth characteristics, microbial population, root colonization and leaf nutrient status was evaluated. The inoculation of seedlings to G. fasciculatum and AZ₁ increased all growth characteristics (plant height, stem diameter, leaf area and total root length), microbial consortium of the rhizosphere soil and leaf N, P, K and Zn content in all those plots where soil solarization and black plastic mulching was used followed by chemical disinfestations and natural soil conditions at all other mulch types used. These findings suggested that the soil inoculation of G. fasciculatum and AZ₁ strain to seeds and/or the saplings under soil solarization with black plastic mulch attained a desirable plant height and become ready for grafting which however saved a period of 1 year for nursery management compared to traditional nursery raising practice, and thus, it may be a viable and feasible approach to maintain soil productivity under nutrient limited soils for sustainable apple nursery production under temperate rain-fed conditions.     

Assessment of Genetic Diversity in Feronia limonia (L.) Swingle Using Inter Simple Sequence Repeats

ABSTRACT

Genetic variation was studied in threatened natural populations of Feronia limonia (Rutaceae). Samples were collected from 3 populations located in the Aravalli mountain range of south-east Rajasthan, India. Using 25 Inter Simple Sequence Repeat (ISSR) primer combinations, significant diversity was characterized among the individuals. Analysis of Molecular Variance (AMOVA) revealed that diversity is partitioned mainly within population components (80%). F statistics showed that low but significant amount of gene flow is taking place between populations (φ_ST = 0.21, P < .001). The study highlights the utility of ISSRs in assessing diversity of populations that are fragmented or limited in size.     

Assessment of genetic diversity in common bean (Phaseolus vulgaris L.) germplasm using amplified fragment length polymorphism (AFLP)

AFLP technique was applied to assess genetic diversity among 44 common bean accessions that included 6 exotic accessions, 15 Indian land races and 23 released varieties. Eight AFLP primer pairs were used that produced 820 products of which 698 were polymorphic (85.12%). Wide variations were observed among all the accessions for the number of amplification products, percent polymorphism and average polymorphism information content (PIC). The Jaccard's similarity indices (J) based on the AFLP profiles were subjected to UPGMA cluster analysis. The dendrogram generated revealed seven major groups. Seventeen out of 23 released varieties were restricted to clusters VI and VII. The value of r = 0.934 in Mantel's test for cophenetic corrlelation applied to the cluster analysis indicated the high fitness of the accessions to a group. The germplasm used in the present study had narrow genetic base, although moderate to high genetic diversity was observed. The details of diversity analysis and the potential use of Indian common bean accessions in common bean breeding programme are provided in the present study.     

Comparative analysis of diversity based on morpho-agronomic traits and microsatellite markers in common bean

Morpho-agronomic traits and microsatellite markers were used to survey genetic diversity in 115 common bean genotypes that included 70 Indian landraces, 24 released varieties and 21 exotic accessions. Twelve morpho-agronomic traits, namely, days to 50% flowering, leaflet length, leaflet width, pod length, pod width, number of pods per plant, days to maturity, seed length, seed width, number of seeds per pod, 100 seed weight and seed yield per plant were studied. Field data of two consecutive years were subjected to multivariate analysis as proposed by Mahalanobis’s D²-statistics, Tochers method of clustering and combined analysis of variance. Seventeen microsatellite markers were also used to examine genetic diversity at molecular level that showed polymorphic information content (PIC) in the range of 0.00–0.684. Dendrograms based on Euclidean distances and UPGMA analysis showed the presence of majority of released varieties into single cluster, which pointed toward their low genetic base in comparison to indigenous landraces and exotic germplasm. Significant correlation existed between morphological genetic distance and microsatellite genetic distance tested by Mantel test (r = 0.876).     

A PCR-based assessment of genetic diversity,and parentage analysis among commercial mango cultivars and hybrids

Summary

Three different PCR methods [Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR), and Directed Amplification of Minisatellite DNA (DAMD)] were used to analyse genetic diversity and parentage among 20 mango cultivars, including 18 landraces and two hybrids (‘Amrapali’ and ‘Mallika’). These hybrids together with a third hybrid (‘Ratna’), and an out-group species (Mangifera sylvatica) were also analysed for parentage. Fifteen, seven and four primers were used to amplify a total of 158, 69 and 59 distinct DNA fragments by RAPD, ISSR and DAMD, respectively. Of these, approx. 85%, 64% and 90% were polymorphic, respectively. Genetic distances between pairs of mango cultivars were measured separately by each method and depicted graphically as a Neighbor Joining (NJ) tree. The three methods revealed different groupings of cultivars and hybrids. A NJ tree based on the cumulative data from all methods correlated well with the parentage of the mango hybrids, and the grouping of cultivars on a regional basis. Genetic markers likely to be associated with important agronomic traits were identified by further analysing the hybrids, with their respective parents, using all three methods. On the basis of the highest number of polymorphic bands observed (90%), DAMD was judged to be the best method with which to analyse mango germplasm.     

Comparative study of conventional and artificial neural network-based ETo estimation models

Accurate estimation of reference crop evapotranspiration (ETo) is required for several hydrological studies and thus, in the past, a number of ETo estimation methods have been developed with different degree of complexity and data requirement. The present study was carried out to develop artificial neural network (ANN) based reference crop evapotranspiration models corresponding to the ASCE’s best ranking conventional ETo estimation methods (Jensen et al. ASCE Manual and Rep. on Engrg. Pract. no. 70, 1990). Among the radiation methods, FAO-24 radiation (or Rad) method for arid and Turc method for humid region, and among the temperature methods, FAO-24 Blaney–Criddle (or BC) method were studied. The ANN architectures corresponding to the above three less data-intensive methods were developed for four CIMIS (California Irrigation Management Information System) stations, namely, Davis, Castroville, Mulberry, and West Side Field station. The comprehensive ANN architecture developed by Kumar et al. (J Irrig Drain Eng 128(4):224–233, 2002) corresponding to Penman–Monteith (PM) ETo for Davis was also tried for the other three stations. Daily meteorological data for a period of more than 10 years (01 January 1990 to 30 June 2000) were collected from these stations and were used to train, test, and validate the ANN models. Two learning schemes, namely, standard back-propagation with learning rate of 0.2 and standard back-propagation with momentum having learning rate of 0.2 and momentum term of 0.95 were considered. ETo estimation performance of the ANN models was compared with the FAO-56 PM method. It was found that the ANN models gave better closeness to FAO-56 PM ETo than the best ranking method in each category (radiation and temperature). Thus these models can be used for ETo estimation in agreement with climatic data availability, when not all required climatic variables are observed.