Zinc and Boron Application at Different Phenological Stages Alleviates Tree Growth,Fruit Yield and Quality of Sweet Orange Cv. ‘Blood Red’

The deficiency of micronutrients, particularly zinc (Zn) and boron (B) has affected vegetative growth, yield and fruit quality of sweet orange in many citrus growing areas of Pakistan. The present study was conducted in 2015 and 2016 to determine the impact of Zn and B supplementation on growth and quality of sweet orange cv. ‘Blood red’. Pre-harvest foliar application of variant Zn and B levels was done at different phenological stages of fruit growth and development, i.e., full bloom, fruit set and premature stage. Results have concluded that pre-harvest foliar application of Zn and B augmented phosphorous, Zn, B, potassium, iron, and manganese contents in leaves, particularly Zn and B content from deficient to optimal level. Moreover, the combined application of Zn and B has also significantly enhanced vegetative characters such as tree height and spread along with reproductive characters, i.e., incremented numbers of fruit, fruit weight, total soluble solids, titratable acidity and ascorbic acid contents. However, among stage comparison, outcomes depicted that foliar application of Zn and B at full bloom?+?fruit set?+?premature stage resulted in maximum production with high quality fruits.

     

Vegetative,Chemical Status and Productivity of Zucchini Squash (<Emphasis Type=Italic>Cucurbita pepo</Emphasis> L.) Plants in Responses to Foliar Application of Pentakeep and Strigolactones Under NPK Rates

In order to determine the effect of two bio-stimulants under NPK fertilizer rates on growth and nutrient content and yield of zucchini (squash), an experiment was conducted at Mendel university during 2014. The treatments included four NPK rates namely, 0, 75, 100 and 150% of recommended rate in combination with foliar application of Pentakeep super and strigolactones (alone and in combination) were used. This study was arranged in a split plot design in three replications. The results showed NPK at 150% led to the maximum significant increase of growth characters i.?e., leaf number, fresh and dry weight of leaves relative to unfertilized control. Chlorophyll reading increased significantly with increase in NPK supply up to NPK75%. The highest contents of N, K and nitrate were found in zucchini leaves treated with NPK at 150% of recommended rate. Yield and its component increased significantly with increase in NPK supply up to 100% of recommended rate. The combined application of Pentakeep super and strigolactones significantly maximized growth characters and fruit yield as compared to control treatment. The highest content of N generated in plants sprayed with Pentakeep super while application of Pentakeep and strigolactones did not affect the P and K contents. Whereas, control plants effectively significantly increased the chlorophyll and nitrate content of leaves.     

The Effect of Growth Regulators and a Biostimulator on the Health Status,Yield and Yield Components of Potatoes (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)

In this study, the influence of potato cultivars Irga, Satina, Valfi, Blaue St. Galler and Highland Burgundy Red (HB Red), growth regulators: Bio-Algeen S?90, Kelpak SL and Trifender WP, and the biostimulator Asahi SL on the health status of potato plants and tuber yield was investigated. The severity of late blight and early blight was estimated during the growing season. After harvest, potato tuber yield was determined according to size fractions. The applied treatments significantly reduced the severity of late blight in cv. Irga (Kelpak SL), Valfi (Bio-Algeen S-90, Kelpak SL, Trifender WP) and Blaue St. Galler (Trifender WP) in 2013. In 2015, the symptoms of early blight were significantly reduced in cv. Irga after the application of all tested bioregulators. HB Red was characterized by the best health status among the evaluated cultivars. Kelpak SL and Bio-Algeen S-90 increased the tuber yield of cvs. Irga and HB Red, respectively, in 2013, and Trifender WP increased the tuber yield of cv. Satina in 2014. In the first year of the study, the applied growth regulators and biostimulator significantly increased the percentage of medium-sized tubers of cv. Blaue St. Galler, and Bio-Algeen S-90 increased the percentage of medium-sized tubers of cv. HB Red.