479 Fruit Characteristics and Productivity of Date Palm Trees (Phoenix dactylifera L.) as Affected by Some Growth Regulators

Abstract

<jats:p>Date palm trees are among the most plentiful fruit trees in the Arabian Gulf States. Bioregulators have been used for the improvement of quality and productivity of date plam tree fruits. Application of gibberellic acid (GA<jats:sub>3</jats:sub>), naphthalene acetic acid (NAA), and ethephon, separately or in a mixture, has significant effects on fruit set, fruit dry matter percentage, fruit soluble percentage, fruit ripening, and yield of date palm trees. A study was conducted to assess relative effectiveness of GA<jats:sub>3</jats:sub>, NAA, ethephon, and a mixture of growth regulators on some fruit characteristics, and productivity of `Barhee' date plam trees. Five uniform female `Barhee' date palm trees were pollinated on 5–15 Mar. 1994, 1995, and 1996 by placing eight fresh male strands on female spadix centers (flower cluster). Ten flower clusters were used on each tree, and every two flower clusters were subjected to one of the following treatments: control (water), 150 mg·L<jats:sup>–1</jats:sup> GA<jats:sub>3</jats:sub>, 100 mg·L<jats:sup>–1</jats:sup> NAA, 1000 mg·L<jats:sup>–1</jats:sup> ethephon, and a mixture of growth regulators. The fruit set (%), dry matter (%), total soluble solids (°Brix), fruit ripening (%), and fruit weight (kg per bunch and per tree) were measured. The data showed that the application of GA<jats:sub>3</jats:sub> or ethephon on flower clusters of `Barhee' date palm trees had no constant effect on fruit characteristics and productivity of trees. NAA or a mixture of growth regulators reduced fruit dry matter percentage, fruit ripening percentage, and increased fruit weight per bunch and per tree. Spraying `Barhee' date palm flower clusters with NAA or a mixture of growth regulators 20 days after pollination decreased dry matter percentage, fruit ripening, and increased fruit flesh percentage and tree yield.</jats:p>

Effect of bioregulators preharvest application on date palm fruit productivity, ripening and quality

“…It also retarded fruit green color break of Sokary dates. This increment in fruit physical characteristics was also reported by numerous researchers working on different fruit species (Aljuburi et al, 2000;Stern et al, 2006;Aboutalebi and Beharoznam, 2006;Kassem et al, 2011). The improvement in fruit physical properties as a result of the different sprayed growth regulators might be due to their influence in enlarging cell size and enhancing the strength of carbohydrate sink, thus increasing fruit size and weight.…”

“…The increase in fruit total chlorophyll, TSS and total, reducing and non-reducing sugars at rutab or tamar stage and the decrease in acidity at rutab stage, as well as the decrease in fruit carotene content at rutab stage and in fruit acidity at tamar stage obtained in this present study by NAA, GA 3 and CPPU applications might translate their influence in retarding fruit ripening process as mentioned before Aljuburi et al, 2000) working on date palm. Sucrose synthase and invertase may be important in determining sink activity and could play critical roles in both phloem transport and in photosynthetic partitioning in sucrose-translocating plants (Ramezani and Shekafandeh, 2009).…”

Vegetative and Reproductive Growth and Yield of Plukenetia volubilis Plants in Responses to Foliar Application of Plant Growth Regulators

“…However, effect of PGRs on yield and plant development varied from species to species (Rademacher, 2015). A number of PGRs can be powerful tools for improving the growth and yield of oilseed crops as they can in some way modify plant development (Abdelgadir et al, 2010;Aljuburi et al, 2000;Ghosh et al, 1991). It was also reported that although PGR treatments altered the seed demand for resources in sesame, they failed to improve productivity (Day, 2000).…”

Improving yield, quality and storability of “Samani” date palm fruits by some pre- and post-harvest treatments

“…The increasing of fruit chlorophyll using CPUU and NAA application comparing to control treatment (without growth regulators) may be due to their influence in delayed fruit ripening process as mentioned before (Moustafa and Seif, 1996; Aljuburi et al, 2000) working on date palm. The results is in harmony with (Kassem et al, 2012) who studied spraying Sokary date palm growing in Riyadh area, Saudi Arabia by NAA, GA3, CPPU, Put and SA substances increased significantly chlorophyll with all treatments (except Eth) during both seasons.…”

“…The increase in fruit total chlorophyllcontent obtained using NAA, GA3 and CPPU application might be due to their influence in retarding fruit ripening process as mentioned before by (Hussein et al 1996;Aljuburi et al 2000) working on date palm fruit. (h) Carotene.…”