Two field experiments were carried out in El-Mattana Agric. Res. St., Agric. Res. Cent., Luxor Governorate, Egypt during 2010 and 2011 seasons to study the response of Giza 90 cotton cultivar to the application of some drought tolerance inducers to increase the tolerance of cotton plants to drought under high temperature condations in Upper Egypt. The experimental design was a split plot with four replications. Main plots included two irrigation intervals (15 and 21 days) and sub plot included the foliar application of four drought tolerance i.e CaBoron, Pix, Humex and Methanol) and a control (untreated plants), The obtained results could be summarized as follows: Irrigation every 15 day significantly increased plant height, no. of fruiting branches/plant, no. of days to first flower and first open boll. Prolonging irrigation interval to 21 day significantly decreased no. of open bolls /plant, boll weight, seed index, seed cotton yield/fed., fiber length, uniformity index and fiber strength, but lint % was significantly increased. All drought tolerance inducers significantly increased plant height, number of fruiting branches and open bolls/plant, boll weight, seed index, seed cotton yield /fed., earliness %, fiber length, uniformity index and fiber strength as compared with the untreated plants. In general, plants which were sprayed with methanol gave the highest averages of growth, yield and its components and earliness %, followed by plants which were sprayed with CaBoron, while the Pix sprayed plants came the last in this respect in both seasons. Well watered plants every 15 day showed greater response to Methanol than to any other drought tolerance inducer, while the plants irrigated every 21 day and treated with pix gave the lowest average in this respect. The interaction between studied factors had a significant effect on fiber strength in both seasons and upper half mean length in the first season only. Finally it could be concluded from this study that the CaBoron, Humex, Pix and Methanol applications to plants under normal and water stress conditions could induce drought tolerance of cotton plants and in turn improved plant growth, fruiting and yield particularly under water stress and high temperature conditions.

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 P 2 O 5 + 24 kg K 2 O/fed; 75 kg N + 30 kg P 2 O 5 + 36 kg K 2 O/fed and 90 kg N + 37.5 kg P 2 O 5 + 48 kg K 2 O/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 P 2 O 5 + 48 kg K 2 O/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 i...

Two field experiments were carried out at Sids Agric. Res. Station, Beni-Suef Governorate, in 2007 and 2008 seasons, to study response of growth, fruiting and yield of the Egyptian cotton cultivar Giza 80 (G. barbadense L.) to foliar application with indole acetic acid (IAA) and Kinetin (a synthetic cytokinin). Besides the control treatment, two concentrations of each of IAA (25 and 50 ppm) and kinetin (10 and 20 ppm) and their combinations were application twice, at the start and peak of flowering stages. Results revealed that, cotton plants treated with various treatments of IAA and/or kinetin showed higher leaves content of chlorophyll a, b and total chlorophylls than those of untreated ones. However, only some treatments of IAA and/or kinetin significantly increased plant height, numbers of fruiting branches/plant and open bolls/plant in both seasons; number of main stem nodes and seed cotton yield/fad., in 2007 season only; and total fruiting sites/plant and seed index in 2008 season only, but they significantly decreased fruit shedding% and earliness% in 2007 season only. Application 50 ppm IAA alone significantly decreased earliness% in 2007 season, and either alone or with kinetin at both levels gave the highest values of plant growth parameters, but their effects on fruit shedding and yield did not reach the significant level. In general, the most consistently positive effects on plant fruiting and seed cotton yield were given by application 25 ppm IAA alone or 20 ppm kinetin alone or both.

Two field experiments were carried out at El-Gemmeiza Agricultural Research Station, El-Gharbia Governorate in 2014 and 2015 seasons, to study the effect of nano-fertilizer (Lithovit) rates (0, 2.5, 5 and 7.5 g/l) and foliar potassium fertilizer (in the form of Potasin-P) rates (2.5, 5 and 7.5 cm 3 /l) under three planting dates (8 April, 8 May and 8 June) on leaves chemical composition of the Egyptian cotton (Gossypium barbadense L.), cultivar Giza 86. Cotton plants were foliar sprayed with Lithovit and Potasin-P at 45 and 60; 46 and 61 days after planting, respectively. Leaves N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly affected by planting date in both seasons, in favour of early planting date (8 April) compared to medium and late planting dates (8 May and 8 June). Delaying planting date significantly increased leaf proline content and leaf peroxidase activity which indicate the presence of heat stress effect on the plant.Leaves N, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly affected by rates of Potasin-P in both seasons, in favour of the medium rate of Potasin-P (5cm 3 /l). While, leaves P and K contents were significantly increased by using the high rate of Potasin-P (7.5cm 3 /l). The medium rate of Potasin-P (5cm 3 /l) significantly decreased leaf proline content and peroxidase activity which indicate favorable plant conditions.Leaves N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly increased by each increment of nano-fertilizer (Lithovit). The inverse was true in leaf proline content and peroxidase activity. The decrease in these traits induced favorable plant conditions and reflected on reduce environmental stress effect.The second order interaction had a significant effect on all studied chemical composition of leaves. Cotton plants sown on 8 April and sprayed with 5cm 3 Potasin-P /l and 7.5 g Lithovit/l recorded the highest values of N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates content in leaves. In the contrary, this interaction recorded the lowest values of leaf proline content and peroxidase activity which induced favorable plant conditions and reflect on reduce environmental stress effect. It can be concluded that the mentioned interaction was the recommended treatment for optimum chemical composition of cotton leaves under experimental conditions.

The field experiments were conducted at Sakha Agricultural Research Station at Kafr El-Sheikh Governorate, Egypt, during the growing seasons of 2009 and 2010 to preparing the suitable agricultural managements practices (planting date, plant population (hill spacing) and nitrogen fertilizer level) for new promising hybrid cotton (Giza 77 x Pima S 6). The first experiment (detriment the suitable planting date) was grown under three planting dates 1 st April, 15 th April and 1 st May. The randomized complete block design was used with four replications. The second experiment (detriment the suitable plant population (hill spacing) and nitrogen fertilizer level) were grown under split plot design. The main plots involved the three hill spacing (20, 25, and 30 cm between hills) and the sub plots included three nitrogen fertilizer levels (45, 60 and 75 kg N /fed.). The results indicated that early planting date in 1 st April significantly increased seed cotton yield/fed. due to the increase of number of open bolls /plant and boll weight. Increasing hill spacing from 20 to 30 cm (decreasing plant population) significantly increased number of sympodia /plant, number of open bolls /plant, boll weight and seed cotton yield /fed. While plant height, first sympodial position, earliness % and lint % decreased. As for nitrogen levels, plant height, number of sympodia /plant, first sympodial position, number of open bolls /plant, boll weight, seed index and seed cotton yield/fed. increased by increasing nitrogen levels. The interaction between plant population (hill spacing) and nitrogen fertilizer levels gave significantly effect on all character studied except lint % and fiber properties. The interaction 30 cm between hills and 75 kg N /fed gave the highest number of sympodia plant, number of open bolls, boll weight, seed index and seed cotton yield /fed. The studied treatments did not exhibit any significant effect on all fiber properties. It could be concluded that the highest seed cotton yield/fed. was obtained from planting the new promising hybrid cotton Giza 77 x Pima S 6 early in 1 st April under 30 cm hill spacing and 75 kg N/fed. under Sakha location.