Response of Different Concentrations of Liquid Pollen Applications on Fruit Set, Yield and Fruit Physical Properties of Dhakki and Zahidi Date Palm (Phoenix dactylifera L.) under the Agro-Ecological Conditions of Dera Ismail Khan

The main cause for low fruit set % retaining ability, fruit weight and fruit yield per plant is the improper pollination in most of the commercial date palm varieties in different date palm growing countries of the world. A trial was conducted throughout cropping season (Feb-August) in 2020 at the Date Palm Research Orchard, Gomal University, Dera Ismail Khan, Pakistan. The main objective was to assess the response of different concentrations of liquid pollen application on the fruit set, yield, and quality of Dhakki and Zahidi cultivars of date palm. The experiment was planned in R.C.B.D with split plot arrangement. Two date palm cultivars (Dhakki and Zahidi) were considered as main factor and four pollen concentrations as sub factor, repeated thrice. For pollination, a single pollen source was used. The three spathes of each Dhakki and Zahidi palms were fertilized by following the suspended pollen spray method using 2, 4, 6 and 8 g pollen L-1 water. In addition, 2 g sugar was added to make the solution sticky. A large set of para-meters were investigated. These included: fruit set (%), days to fruit set, fruit weight (g), fruit size (length and breadth (cm)), pulp weight, seed weight (g), seed size (length and width (cm)), fruit drop (%), days to maturity, bunch weight (kg), fruit yield (kg plant-1). Results of this study revealed that the maximum days to fruit set (23.40 and 22.10), fruit set (96.47 and 91.46%), fruit drop (43.7 and 26.81%), bunch weight (11.13 and 6.41 kg), and fruit yield (178.13 and 64.13 kg plant-1) was recorded with the maximum pollen strength of 8 g L-1 in both the cultivars Dhakki and Zahidi, respectively. On the other hand, the minimum values of these parameters were showed by the pollen strength of 2 g L-1 in both the date palm cultivars. Overall, the cultivar Dhakki achieved maximum values of fruit quality traits with fruit size, fruit weight, and pulp weight. Hence, based on this study, the liquid pollen application of 8 g L-1 is suggested for attaining maximum fruit set and yields in date palm under the Agro-ecological situations of Dera Ismail Khan