Wheat
The decomposing wheat residues contain primary organic acids such as phenolic acid. Wheat residues added 1.5 tonnes phenolic acid per acre under no tillage condition.
Wheat straw inhibited seed germination, decreased root and shoot growth, shortened internodes and reduced the grain yield of wheat.
Decomposing of wheat straw may inhibit the root growth of barley.
The residues of the wheat contains acetic acid, butyric acid and iso butyric also have the number of phenolic acids.
Decomposition of the wheat residues in the aerobic condition stimulate the root growth of barley seedling but in the anaerobic condition inhibit the growth of roots due to the higher conc. of the acetic acid.
Corn
Decomposing of corn residues decreased the respiration of tobacco seedlings and causes chlorsis and stunted growth of maize and inhibited the nitrification process in the soils.
Butyric acid, vanillic acid and salicylic acids are present in the corn residues
Rice
The allelochemicals released by the decomposition of the rice residues cause the effect on the growth of rice seedling and decreased the yield of rice. Nodulation process, biological nitrogen fixation and grain yield also reduced in soybean by rice stubbles.
Residues of the rice have vanillic and butyric acids
Rye
Decomposition of rye residues inhibits seed germination, seedling emergence and radical elongation of the rye seedling.
Butyric and benzoic acids are present in the rye residues
Oat
Oat straw was more toxic at the maturity and its toxicity remains up to 8 weeks after decomposition.
Aqueous extract of decomposing oat residues were inhibitorier to seedling growth of the test species.
Sorghum
It proves harmful for the maize, oat and wheat growth. It proved inhibitorier to small seeded, broad leaf species. The aqueous extract of sorghum stubble inhibited the seed germination and root growth.
Barley
Decomposing barely residues became phytotoxic 7-10 days after incorporating in the soils toxicity reached peak at 20 days and declined after 45 days.
Benzoic acid present in the residues of the barley
Clover
Aqueous extract of clovers caused poor and abnormal seed germination and depressed seedling growth.
Soybean
Soil microorganisms form the inhibitory substances from the decomposing of the soybean residues. An aqueous extract inhibit the seed germination soybean, alfalfa and many other.
Leucine and valine acids found in the soybean
Sunflower
Reduced the growth of sorghum seedling
Inhibit the seed germination
Brassica oilseed crop
Stunted the plant and reduced the dry weight
Inhibition of germination
Sugarcane
Inhibit the growth of young sugarcane plant
Decrease the stem and leaf growth
Acetic, vanillic and oxalic acids are present in the sugarcane residues
Tobacco
Effect on germination, root and shoot length and seedling vigor of rice
Increased the height, specific leaf weight and chlorophyll content in maize
By.
Israr Masood* and Imran Ramzan1
*Author Department of Soil and Environmental Sciences, 1 Co-author Department of Agronomy, University of Agriculture Faisalabad, Pakistan
