Incidence of Jelly Seed Disorder in ‘Tommy Atkins’ and ‘Van Dyke’ Mangoes as Affected by Agro-Ecological Conditions in Kenya

Abstract

Jelly seed disorder is one of the major problems in mango production in Kenya as well as other mango producing countries in the world. This problem manifests itself through breakdown of tissues around the seed of the affected fruits resulting in unmarketable fruits. Although the exact cause of jelly seed in mango is unknown, some reports indicate that the condition could be due to imbalance related to Ca, Mg, N and K supply to the fruit. To establish the extent of this problem in Kenya, a study was conducted in 2013 in three major mango producing counties located in different agroecological zones namely Embu, Murang'a and Meru. Three farms with homogenous trees of "Tommy Atkins" and "Van Dyke" mangoes were randomly selected per county. Soil and mango leaf analysis were carried out to determine the nutrient status. Rainfall and temperature data were also recorded during the study period. At harvest time, 50 tree-ripe fruits of each variety were randomly sampled from 25 trees per site and sliced along the endocarp to expose the seed then visually examined and scored for the incidence of jelly seed using Galan Sauco scale. Soil analysis showed Original Research Article

Yield and Tissue Calcium Concentration of Mango (Mangifera indica L.) Fruit as Influenced by Calcium Source and Time of Application

“…The increase in the yield by application of calcium could be attributed to the role of calcium in cell formation and its prevention of cellular degeneration [5,6] Calcium is an important mineral in the formation of cell membrane and development hence increases in the fruit physical attributes. This was in agreement with previous studies as reported by [7,16,17,18,19,20,21]. These results are contradictory to those reported by [11,22] who reported no increase in weight and yield of fruits by application of calcium.…”

“…This study was conducted in fruiting seasons 2017 and 2018 at Karurumo orchard Embu County, Kenya. The area has an elevation of 1174 m asl of coordinates 0° 32́ S 37°41 E [7] classified as lower midland 3 (LM3). This area receives an annual rainfall of 1206 mm, with a bimodal pattern and an average annual temperature of 22.7°C.…”

“…This area receives an annual rainfall of 1206 mm, with a bimodal pattern and an average annual temperature of 22.7°C. The soils in this area are loamy sand to clay ferralic arenosal that have been found to have low levels of calcium [7].…”

“…While there are studies that link increase in flesh calcium concentration with calcium spraying, [11] reports on the contrary. Previous studies indicate calcium deficiency in various mango growing sites in Kenya [7].…”

“…Calcium is an important component of the cell wall where, it plays an important role in the formation of individual cells and prevents cellular cells degeneration [5,6]. Previous studies directly link an increase in yields with calcium application [7]. Calcium chloride and calcium nitrate compounds have been reported to be applied in various fruits including papaya [8] and guavas.…”