Two field experiments were carried out at Sakha Agricultural Research
Station 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 water
stress and foliar feeding with boron and zinc under NPK fertilizer levels on
growth, earliness, yield, yield components and some fiber quality. Each
experiment was laid out in a split split-plot design with four replications. The
main plots involved three irrigation intervals (two weeks, three weeks and four
weeks) throughout the growing season. The sub-plots were allocated to three
NPK levels (60 kg N + 22.5 kg P2O5 + 24 kg K2O/fed; 75 kg N + 30 kg P2O5 + 36 kg
K2O/fed and 90 kg N + 37.5 kg P2O5 + 48 kg K2O/fed ) The sub sub-plots involved
four foliar feeding treatments with boron and zinc(control (without foliar
application), foliar application of Zn-EDTA, foliar application of B-EDTA. and
foliar application of Zn-EDTA + B-EDTA). The timing of foliar applications
were 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 weeks
significantly decreased days to first flower, plant height at harvest, no. of fruiting
branches/plant, no. of open bolls/plant, boll weight and seed cotton yield/fed. in
both seasons and days to first open boll in one season only. While, irrigation
intervals did not exhibit significant effect on no. of monopodia/plant, first fruiting
node, earliness %, seed index, lint presenting and fiber properties under study.
2) The obtained results revealed that the high NPK fertilizer level (90 kg N + 37.5
kg P2O5 + 48 kg K2O/fed.) significantly increased first fruiting node, days to first
flower 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 significantly
decreased earliness % in both seasons and did not exhibit significant effect on no.
of monopodia/plant, seed index, lint presenting and fiber properties under study
in both seasons.
3) The obtained results revealed that foliar feeding with boron and zinc mixture
significantly increased no. of fruiting branches/plant, no. of open bolls/plant, boll
weight and seed cotton yield/fed. While, micronutrients treatments did not exhibit
significant effect on plant height at harvest, no. of monopodia/plant, first fruiting
node, days to first flower and first open boll, earliness %, seed index, lint
presenting and fiber properties under study in both seasons.
4) The interaction between irrigation intervals and NPK fertilizer levels
significantly 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 effect
on first fruiting node, days to first open boll, seed index, lint presenting and fiber
properties under study in both seasons.
5) The interaction between NPK fertilizer levels and foliar feeding with some
micronutrients treatments significantly affected no. of open bolls/plant and seed
cotton 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 under
study in both seasons.
6) The interaction between irrigation intervals, NPK fertilizer levels and foliar
feeding with some micronutrients treatments had a significant effect on no. of
fruiting branches/plant and no. of open bolls/plant in 2013 season only and boll
weight and seed cotton yield/fed in both seasons. While, did not exhibit
significant effect on the other traits under study in both seasons.
Generally, results obtained revealed that irrigation every two weeks in
combination with the high NPK fertilizer level (90 kg N + 37.5 kg P2O5 + 48 kg
K2O/fed.) and foliar feeding with Zn and B mixture (2 g from each element/L
water) at the start and peak of flowering stages for obtaining high productivity of
the new promising genotype cotton (Giza 86 x 10229) under this study.