Sesame, the Queen of oil seed crops, plays an important role in the oil seed economy throughout the world. It is adapted to Pakistan’s soil and climatic conditions and Pakistan stands fifth among the growing nations. Between January and March 2024, China imported sesame seeds worth over $10.37 million.
According to The Ministry of National Food Security and Research, sesame has emerged as a vital cash crop within Pakistan’s agricultural portfolio.
Sesame seed is a rich source of protein (20%) and edible oil (50%), and contains about 47% oleic acid and 39% linolenic acid. Its oil has high nutritional and therapeutic value.
Sesame suffers from many diseases. All plant parts are attacked by pathogens. Major diseases affecting sesame in Pakistan are Phyllody, stem and root rot, collar rot, and Fusarium wilt.
Insects also damage crops like mirid bug, jassid, thrips, capsule borer, cotton mealy bug, and termites.
There are various causative organisms of these diseases. Among them, fungi are the most serious. Some of the diseases that cause severe harm to sesame are:
Charcoal Rot is also known as stem and root rot. It is caused by Macrophomina phaseolina, which is one of the major diseases that cause 25-30% of production losses annually. All stages of crop growth are affected by the disease, although the maturity stage is most affected. The disease firstly appears as lower leaf yellowing, which is followed by drooping and defoliation.
Dark black lesions appear in the stem region near the ground, followed by shredding. Mature plants that are affected can be removed easily, leaving the rotting lateral roots in the ground. The disease results in early seed pod opening, drying up, and blackening. There are endless tiny black sclerotia present in the tissues of the rotting root and stem. Management includes cultural practices and the use of fungicides.
Sesame Phyllody Disease is a serious threat to production in the most important sesame-producing areas of the world. Phyllody is a serious disease of sesame in Pakistan, and is caused by a phloem-limiting bacteria phytoplasma and is transmitted by leafhopper . The reported yield loss of the disease is upto 80% yield.
The symptoms of disease include shoot overgrowth, virescence, foliar yellowing, shortened internodes, smaller leaves, thickening of veins, twisting of stem, deformation of capsule, abnormal floral organs, generalized stunting, phloem necrosis, and plant decline. Under severe condition cracking of seed capsule, germination of seeds within capsules, and floral malformation like abnormal green structures in place of normal flowers were also noticed.
This is controlled by removing the attacked plants from the field and using fungicides.
Sesame Fusarium Wilt Disease is one of the most damaging disease of sesame production caused by Fusarium oxysporum f. sp. sesame which causes great yield losses more than 50%.
The disease appears as yellowing, drooping and withering of leaves. The plants gradually wither, show wilting symptoms leading to drying. The infected portions of root and stem show long, dark black streaks of vascular necrosis.
Management includes cultural practices and use of fungicides.
Whitefly, Capsule Borer, Jassid, Mirid Bug, and Trips are major insect pests in sesame crops. Whitefly causes significant yield losses by sucking cell sap from leaves, flowers, and pods, causing leaf curling, stunted growth, and abnormal leaf tissue.
Capsule Borer is active from germination to harvest, causing severe damage during dry seasons and flowering. Jassids suck cell sap from the lower side of leaves, causing yellowing, drooping, and leaf curling. Mirid bugs suck cell sap from flowers and newly born leaves, causing yellowing, drooping, and leaf damage. Trips-sucking insects damage the crop by sucking cell sap from the underside of leaves, causing leaves to dry and appear shiny. These insects are controlled by the spraying of insecticides.
Name: Muhammad Yousaf
Reg# 2021-ag-6645
Semester: 6
Department: Plant Breeding and Genetics
Faculty: Agriculture
Institute: University of Agriculture, Faisalabad
Supervisor: Dr. Muqaddas Aleem