of 28

  • date post

  • Category


  • view

  • download


Embed Size (px)


  • Slide 1
  • Slide 2
  • Abstract Time and stage of harvest of crop play greater role in attaining good crop produce. Premature or delayed harvest adversely affects quality and quantity of produce. Factors considered for time of harvest are economic part aimed, products utility and post harvest storage. All the crops are having certain criteria(physiological maturity and harvest maturity symptoms)for harvesting the produce. All over the globe, different method viz., manual and mechanical methods are practiced depending upon the purpose, time and labour availability. Learning objectives To learn the criteria for harvesting and maturity symptoms of various crops To study the harvesting time, stage, methods and machineries available for harvesting. NextPreviousEnd
  • Slide 3
  • Introduction Time of crop harvest is one of the most important strategy influences yield, quality and storage of crop. Premature or delayed harvest often adversely affects quality of the produce. Pre-mature or immature harvest is desirable for certain products that are preferred juicy and succulent. Produce may become more fibrous and tough or hard if harvested at full maturity, as in the case of pulse crops for vegetable purpose and millets for consumption as fried grain. If the crops such as cereals, pulses and oilseeds are left in the field for too long after maturity, the crop will be predisposed to pests and germination is inevitable due to vagaries of weather. There are different stages for various crops, which demarked as maturity stages, harvesting in those stages gives high income and good quality produce. Farmers are following traditional techniques for harvesting the crops produce, but advancement of science and technology gave way for new innovation and equipments and machineries for harvesting the produces. NextPreviousEnd
  • Slide 4
  • Slide 5
  • Time Of Harvesting Reaping what has been sown is literally known as harvesting. Yields are expected to be high in crops. In order to realize the expected yield, the crop must be harvested when the economic product is at its optimal quantity and quality. Generally, crops are harvested when they are said to be mature. Ideal time to harvest depends on a number of factors, including the economic part, utilization of the product and post harvest storage. Economic part The economic product could be the grain, root, leaf, stem or other parts for different crops. Translocation of the stored food from parts of economic importance to other parts will reduce the yield of desired products. Crops are to be harvested when the desired product is at its maximum quality and quantity. (Cont).. NextPreviousEnd
  • Slide 6
  • Utilization Economic product may be same, but, it may be desirable to harvest in fresh or dry. Maize may be harvested fresh or dry, depending on the intended use. Similarly pigeon pea, cowpea, peas etc. The purpose of growing the crop determines when it is best to harvest it in order to have the highest quality and quality of the desired product. Post harvest storage Harvested produce often requires some form of storage at the site of production, before disposal. The produce may deteriorate in such storage if harvested at improper moisture content. There must be supplementary drying facilities for drying the produce to safe moisture content for storage. NextPreviousEnd
  • Slide 7
  • Maturity Crops can be harvested at physiological maturity or at harvest maturity or storage maturity depends on situation or need of produce Physiological maturity Crop is considered to be at physiological maturity when the translocation of photosynthates is stopped to economic part. It refers to a developmental stage after which no further increase in drymatter in the economic part. In cereals, moisture content of grains is very high during milking stage and it gradually deceases due to accumulation of photosynthates. NextPreviousEnd
  • Slide 8
  • . A steep fall of moisture content from 40% to 20% is an indication of attaining physiological maturity. At this stage, translocation of carbohydrates is stopped due to formation of abscission layer between rachis and grain. At this stage, plant reaches maximum dry weight, increasing production inputs doesnt produce any gains in yield. The grains at this stage are of hard dough consistency. If grain is harvested prior to its physiological maturity, it would have low drymatter, poor quality and will shrivel upon drying. Various crops have different indicators of maturity. NextPreviousEnd
  • Slide 9
  • Physiological maturity symptoms of some field crops Rice Golden yellow colour of the grain and senescence of lower leaves Wheat Complete loss of green colour from the glumes before physiological maturity. Centre spikes are used as indicator grains. BarleyLoss of green colour from the glumes or peduncle MaizeBlack layer in the placental region of corn kernels SorghumBlack layer formation in the placental region of grain Pearl milletAppearance of bleached peduncle in some varieties RedgramGreen pods turning brown, about 25 days after flowering SoybeanLoss of green colour from leaves GroundnutDevelopment of black colour in the inner shell of the pod PulsesTurning of green pods to brown colour NextPreviousEnd
  • Slide 10
  • Harvest Maturity Harvest maturity for a crop is when the product of interest is at best quality and maximum yield. Determining maturity, the highest yield of the produce may be the best indicator followed by the farmers. In certain grains, harvesting is done around 25% moisture, But, in most cases, harvesting grain crops is at 15 to 18% moisture. When the crops are grown for forage, the best time for harvest is when the crop has attained maximum vegetative yield, coupled with high quality. It is best to cut cereal crops at ear- heads emerging stage for fodder. ( Cont) Harvest maturity of sorghum NextPreviousEnd
  • Slide 11
  • Harvest maturity generally occurs 7-10 days after physiological maturity. The important process during this period is loss of moisture from the plants and grains. The general symptoms of harvest maturity are yellowing of leaves, drying of grains or pods. Crop is harvested at physiological maturity when there is need to vacate the field for sowing another crop. Under all other situations, it is advisable to follow harvest maturity. Storage maturity When there is no scope or chance for post harvest drying, the crop is to be harvested at a stage where it can be directly stored. For grains,
  • Harvest maturity symptoms of some important crops RiceHard and yellow coloured grains, golden yellowing of leaves WheatYellowing of spikelets SorghumYellow coloured ears with hard grains Pearl millet & Foxtail millet Compact ears, upon pressing, hard seeds come out Finger milletBrown coloured ears with hard grains PulsesBrown coloured pods with hard seeds inside pods Groundnut Pods turn dark and dark coloured patches inside the shell. Kernels red or pink. On pressing the kernels, oil is observed on fingers. SugarcaneLeaves turn yellow, sucrose content is >10% and brix reading >18% TobaccoLeaves slightly yellow in color, specks appear on the leaves NextPreviousEnd
  • Slide 13
  • STAGE OF HARVEST Determination of harvesting date is easier for determinate crops and difficult for indeterminate crops. At a given time, the indeterminate plants contain flowers, immature and mature pods or fruits. If the harvesting is delayed for the sake of immature pods, mature pods may shatter. If harvested earlier, yield is less due to several immature pods. This problem can be over come by Harvesting pods or ears when 75 %of them are mature, or Periodical harvesting or picking of pods, Inducing uniform maturity by spraying paraquat or sodium salt. (Cont) NextEndPrevious
  • Slide 14
  • Criteria for harvesting of crops Rice 32 days after flowering Less than 4-9% green grains Milky grains - less than 1% Moisture content of grains - less than 20% 80% of panicles are straw coloured and grains in lower portion of panicle is in hard dough stage. Sorghum 40 days after flowering Grain moisture content - less than 28% Pearl millet 28 to 35 days after flowering Maize Less than 22 to 25% moisture in grain Husk colour turns pale brown 25 to 30 days after tassellilng Wheat About 15% moisture in grain Grains in hard dough stage Sugarcane The ratio of brix of top and bottom part of cane must be nearly one Brix - 18 to 20% Sucrose - >10% Redgram 35-40 days after flowering 80-85% of pods turn brown Blackgram and greengram Pods turn brown or black Cotton Bolls fully opened NextEndPrevious
  • Slide 15
  • For deciding harvesting date of fodder crops, some more additional aspects are to be considered. They are: toxins present in the crop, nutritive value, purpose of harvest (whether for stall feeding or for storage) and single or multi-cut. When toxins are present, they are generally high in early stage. Ex. Durrin, a toxic principle present in sorghum is high up to 30 days after sowing. The nutritive value of fodder crop (especially protein content), decreases and fibre content increases with the advancement age of the crop. For stall feeding, crops are harvested when protein content is high and also when the fodder is succulent with more leaves at young stage. Harvesting is delayed by a few more days to get more drymatter if the purpose is hay making. Crops with ratooning abilit