Plum pox virus: diagnosis and spread inhibition by weed control

Journal of Plant Diseases and Protection - Plum pox virus (PPV) is a plant virus (genus Potyvirus, family Potyviridae) infecting stone fruit trees. Since the first report from Bulgaria in 1917, PPV...     

Stability analysis for bollworm complex in <Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.

One approach to improve cotton (Gossypium hirsutum L.) yield is to identify stable genotypes for low or no bollworms damage as it accounts low cost of cultivation to a considerable extent. The objective of the study was to identify stable genotypes for low bollworms damage under protected and unprotected experiments. Fifty cotton (Gossypium hirsutum L.) genotypes were evaluated for open bollworms damage percent (spotted, pink and Heliothis bollworms) for 3 years during 2003–2005 under protected and unprotected conditions. Variance due to genotypes, environments, genotype × environment and genotype × environment (linear) components were highly significant for the trait in protected and unprotected experiments. Under protected experiment, genotypes CSH 3020 and 3045 were found to be desirable and stable while genotype CSH 3058 was suited for poor environments. Fourteen genotypes viz. CSH 3034, 3035, 3043, 3044, 3047, 3051, 3053, 3058, 3059, 3094, 3106, 3114, 3123 and CSH-3157 were fairly stable under unprotected environments. The study lead to the conclude that in general for the two experiments the genotypes differed for stability for low bollworms damage.     

Evaluation of garlic cultivars for salinity tolerance

Salinity tolerance in garlic cultivars was studied in pots. A 50% yield reduction occurs at 5.60-7.80 dS m1, depending on genotype. It was estimated that if soil salinity exceeds 1.70 dS m_l, the mean garlic yield declined by 1.68% per unit increase in soil salinity.     

Effect of exposure to a country liquor (Toddy) during gestation on lipid metabolism in rats

The objective of this study was to determine theeffects of country liquor Toddy and its equivalentquantity of ethanol on lipid metabolism duringgestation in rats. Female rats weighing an average of125 g were exposed to Toddy (24.5 ml/body weight/day)and ethanol (0.52 ml/kg body weight/day) for 15 daysbefore conception and throughout gestation. On the19th day of gestation, altered liver function andhyperlipidemia was seen in both the treated groups.Altered liver function was evidenced by the increasedactivity of alcohol dehydrogenase, aldehydedehydrogenase, glutamic oxaloacetic transaminase oraspartate amino transferase (GOT), glutamic pyruvictransaminase or alanine amino transferase (GPT) andgamma glutamyl transpeptidase (GGT). Hyperlipidemiawas caused by increased biosynthesis and decreaseddegradation of lipids. The incorporation of ¹⁴Cacetate in lipids and activities of HMG CoA reductaseand lipogenic enzymes were elevated and activity ofLPL and bile acids contents were decreased. Toddytreated rats were more severely affected than thosereceiving an equivalent quantity of ethanol. Toddyseemed to potentiate the toxicity induced by alcoholindicating the role of the nonethanolic portion.Hepatic functions were also affected.     

Some studies on the chemical composition of cucurbit kernels and their seedcoats

Chemical composition of the kernels and seedcoats of 8 cucurbit species, viz watermelon, muskmelon, cucumber, pumpkin, spongegourd, bottlegourd, bittergourd and snakegourd have been studied. The proportion of kernels in these seeds ranged from 48.0 to 75.5%. Oil content in kernels varied from 41.0 to 56.5%, protein 28.07 to 34.34%, crude fibre 1.25 to 2.60% and mineral matter 3.01 to 5.01%. Kernels were quite rich in calcium, iron and phosphorus. The cucurbit species compared well with some of the conventional kernels such as cashewnut and almond in their chemical make-up. Although quite low in fat and protein, the seedcoats of these cucurbit species were quite rich in crude fibre and mineral matter and could be of use as animal feed.     

Milk vetch dwarf virus infection in the Solanaceae and Caricaceae families in Southeast Asia

Milk vetch dwarf virus (MDV) is an important member of the genus Nanovirus and is transmitted by the aphid Aphis craccivora. MDV has multiple single-stranded DNA genome components, each approximately 1 kb, and two or three alpha-satellite molecules. It mainly infects plants of the legume family Fabaceae. Recently, papaya (Carica papaya) collected in Yesan, South Korea, displaying symptoms of leaf yellowing and dwarfism, was identified as a new host for MDV. To examine the geographical distribution of MDV, papaya samples with symptoms were harvested in South Korea, Vietnam, and Taiwan in August 2018, along with tomato and pepper samples grown in adjacent fields in Vietnam. The results revealed the presence of MDV not only in papaya but also in pepper and tomato. This MDV infection in members of the Solanaceae family was confirmed by Southern blot hybridization performed using a PCR product of segment S as a probe. Based on sequence analysis of three MDV components (M, S, and C3), we verified the presence of three different isolates of MDV in these three countries and homology between sequences of isolates from papaya and from members of the Solanaceae from Vietnam. Taken together, our results clearly demonstrate MDV infection in Vietnam and Taiwan for the first time and confirm that MDV can infect economically important pepper and tomato.     

Influence of tillage methods and fertilizer application on chemical properties of worm castings in a tropical soil

The effects of four rates of N (0, 40, 80 and 120 kg/ha) and three rates of P (0, 13 and 26 kg/ha) on chemical characteristics of soils and earthworm casts for no-tillage and conventionally disc plowed systems were investigated for a tropical Alfisol. Worm casts contained 2.3 to 1.5 times more organic matter, 1.8 to 1.2 times more nitrogen, 1.6 to 1.3 times more Bray-P, 3.2 to 2.1 times more exchangeable Ca²⁺, 3.8 to 2.5 times more exchangeable Mg²⁺, 3.1 to 2.2 times more exchangeable K⁺, and 1.4 to 1.2 times more exchangeable Na⁺ than the top 10 cm of the soil. The ECEC of worm casts was 3.1 to 2.1 times higher than in the surface soil. The nutrient status of both casts and soil in no-tillage plots was generally superior to that in conventionally plowed treatments. Different rates of N and P application had a significant positive effect on the nutrient status of worm casts. The results are discussed in terms of the role of earthworms in soil productivity.     

Suppression of Botryosphaeria canker of apple by arbuscular mycorrhizal fungi

Stem brown canker or Botryosphaeria canker disease impairs the growth and kills the shoots, limbs and even trunks of infected apple trees. Apple roots are usually colonized by arbuscular mycorrhizal fungi, which may have a positive influence on plant growth and suppression of diseases. In order to assess the efficacy of AM to suppress the disease severity and plant growth enhancement, nine AMF inoculation treatments (Sclerocystis dussi, Glomus intraradices, G. fasciculatum, G. bagyaraji, G. leptotichum, G. monosporum, Gigaspora margarita, a mixed AM culture and a non-mycorrhizal control treatment) were used in this present study. Two-year-old potted apple plants, maintained under glasshouse conditions, were either pre-inoculated with AMF followed by stem inoculation with Botryosphaeria ribis or simultaneously inoculated with Botryosphaeria ribis and AM. The results indicated that the incidence of canker was less severe in plants inoculated with AMF in comparison to non-mycorrhizal control. Timing of inoculation also had a significant effect on disease development and plant survival. Plants pre-inoculated with mycorrhiza performed better over those inoculated simultaneously with Botryosphaeria ribis and AM fungi. Furthermore, AM inoculation resulted in improved survival and growth of AMF-colonized plants; though, it varied by species of AM fungi utilized.     

Water use in rice crop through different methods of irrigation in a sodic soil

Sodic soils are characterized by high exchangeable sodium on exchange sites, soil pH greater than 8.5, relatively low electrical conductivity, low infiltration rate and dispersed clay. These characteristics restrict the capacity of soil to absorb water, resulting in poor infiltration. Evidently, these soils require application of irrigation water at shorter intervals for crop production. Thus, irrigation strategy for sodic soils differs from that of normal soils. An experiment to determine the suitable irrigation strategy along with methods of application namely: surface (farmer’s practice), sprinkler (double nozzle impact sprinkler), and low-energy water application device (LEWA) were initiated in the year 2012 for rice crop. Irrigation depths of 6 cm in case of surface method and 4 cm in case of sprinkler and LEWA methods were applied at each irrigation event. The irrigation events for rice were scheduled at 2-DAD (days after the disappearance of the ponded water), 3-DAD, and 4-DAD through surface method, and at daily, 1- and 2-day intervals (after initial ponding disappeared) by sprinkler and LEWA methods. Sprinkler and LEWA methods resulted in highest rice yield of 4.4 t ha^?1 in irrigated plots at the 2-day interval which was at par with the highest yielding surface-irrigated plot scheduled at 2-DAD. At the same time, irrigation strategy of 2-day interval through sprinkler and LEWA methods registered water saving to the extent of 30–40% over 2-DAD under surface irrigation method. Results revealed that there could be substantial saving of water and energy (electricity and diesel) through the use of sprinkling devices for irrigating rice under sodic soil environments.