EFFECT OF WATER STRESS AND FOLIAR FEEDING WITH BORON AND ZINC UNDER NPK FERTILIZER LEVELS ON GROWTH AND YIELD OF THE NEW PROMISING COTTON GENOTYPE (GIZA 86 X 10229)

Abstract

Two field experiments were carried out at Sakha Agricultural ResearchStation at Kafr El-Sheikh Governorate, Egypt, on new promising cotton genotype(Giza 86 X 10229) during 2013 and 2014 seasons to study the effect of waterstress and foliar feeding with boron and zinc under NPK fertilizer levels ongrowth, earliness, yield, yield components and some fiber quality. Eachexperiment was laid out in a split split-plot design with four replications. Themain plots involved three irrigation intervals (two weeks, three weeks and fourweeks) throughout the growing season. The sub-plots were allocated to threeNPK levels (60 kg N + 22.5 kg P2O5 + 24 kg K2O/fed; 75 kg N + 30 kg P2O5 + 36 kgK2O/fed and 90 kg N + 37.5 kg P2O5 + 48 kg K2O/fed ) The sub sub-plots involvedfour foliar feeding treatments with boron and zinc(control (without foliarapplication), foliar application of Zn-EDTA, foliar application of B-EDTA. andfoliar application of Zn-EDTA + B-EDTA). The timing of foliar applicationswere at the start and peak of flowering stages.The most important results obtained could be summarized as follows:1) The obtained results revealed that increasing irrigation intervals to four weekssignificantly decreased days to first flower, plant height at harvest, no. of fruitingbranches/plant, no. of open bolls/plant, boll weight and seed cotton yield/fed. inboth seasons and days to first open boll in one season only. While, irrigationintervals did not exhibit significant effect on no. of monopodia/plant, first fruitingnode, earliness %, seed index, lint presenting and fiber properties under study.2) The obtained results revealed that the high NPK fertilizer level (90 kg N + 37.5kg P2O5 + 48 kg K2O/fed.) significantly increased first fruiting node, days to firstflower and first open boll, plant height at harvest, no. of fruiting branches/plant,no. of open bolls/plant, boll weight and seed cotton yield/fed and significantlydecreased earliness % in both seasons and did not exhibit significant effect on no.of monopodia/plant, seed index, lint presenting and fiber properties under studyin both seasons.3) The obtained results revealed that foliar feeding with boron and zinc mixturesignificantly increased no. of fruiting branches/plant, no. of open bolls/plant, bollweight and seed cotton yield/fed. While, micronutrients treatments did not exhibitsignificant effect on plant height at harvest, no. of monopodia/plant, first fruitingnode, days to first flower and first open boll, earliness %, seed index, lintpresenting and fiber properties under study in both seasons.4) The interaction between irrigation intervals and NPK fertilizer levelssignificantly affected days to first flower, plant height at harvest, earliness%, no.of open bolls/plant, boll weight and seed cotton yield/fed in both seasons and no.of fruiting branches/plant in one season only and did not exhibit significant effecton first fruiting node, days to first open boll, seed index, lint presenting and fiberproperties under study in both seasons. 5) The interaction between NPK fertilizer levels and foliar feeding with somemicronutrients treatments significantly affected no. of open bolls/plant and seedcotton yield/fed in one season and no. of fruiting branches/plant and earliness %in both seasons and did not exhibit a significant effect on the other traits understudy in both seasons.6) The interaction between irrigation intervals, NPK fertilizer levels and foliarfeeding with some micronutrients treatments had a significant effect on no. offruiting branches/plant and no. of open bolls/plant in 2013 season only and bollweight and seed cotton yield/fed in both seasons. While, did not exhibitsignificant effect on the other traits under study in both seasons.Generally, results obtained revealed that irrigation every two weeks incombination with the high NPK fertilizer level (90 kg N + 37.5 kg P2O5 + 48 kgK2O/fed.) and foliar feeding with Zn and B mixture (2 g from each element/Lwater) at the start and peak of flowering stages for obtaining high productivity ofthe new promising genotype cotton (Giza 86 x 10229) under this study.