The seed production of forage crops is beset with many difficulties since it is a specialized job requiring skill, intimate knowledge of the flowering and seeding behaviour of the species, cutting and grazing-management systems, and above all, the timeliness of the operations. All the tropical and subtropical forage species are, by nature, shy seed-producers. The main problems encountered in the perennial forage grasses are :

1. Prolonged period of growth and flowering.   Owing to the continuous vegetative growth, the tillers between plants and even with plants are at different stages of growth and, accordingly, the panicles or inflorescences are also in different stages of excretion. Therefore, anthesis also occurs at different times.
2. Longer duration of anthesis and spikelet maturity.   It takes a longer time for the completion of anthesis which starts from the top and proceeds downwards. The maturity of the spikelets also follow the same sequence.
3. Abscission of spikelets.   Before the whole inflorescence reaches maturity, owing to the poor spikelet-retention capacity, a lot of immature spikelets are shed. In some of the grasses, even the shedding of mature spikelets takes place, as and when maturity takes place, thereby causing heavy seed losses and making commercial grass-seed production difficult and costly.

In the case of the forage legumes, the main problems which pose hindrances in commercial seed production are :

(i) Diffused flowering and flower-shedding. The flowering in the case of the forage legumes is diffused and is of longer duration, resulting in the formation of pods at different intervals. In addition, there is a heavy shedding of flowers after anthesis in the case of velvet beans, lucerne, field beans. guar (Atylosia, Siratro), etc.
(ii) Uneven pod-setting and maturity. Owing to non-synchronous flowering, pod-formation also takes place at different periods.
(iii) Pod-shedding and shattering. Owing to the continuous vegetative growth, the pods droop down into the vegetative growth of the crop, thereby slowing down the development of pods and delaying pod maturity. Pods on maturity shatter violently, dispersing the seed all around the plants. Thus all these situations call for collecting the ripe pods frequently and finding out remedies for increasing the spikelet-retention capacity of the inflorescences. Thus the seed production industry connected with the forage crops is not making a good headway.

Estimated forage seed requirement.

According to land-utilization statistics (1963-64), the total area under cultivated fodder crop is only 4.4 per cent (6.8 million hectares) and the estimated requirement of seed and plant material in respect of different fodder crops is estimated at 2.0-2.5 million tonnes (Seed Review Team Report, 1968). Similarly there is about 13 million hectares under cultivable wasteland, including the saline-alkaline soils and drought-prone areas. Even if the reseeding programme is undertaken on a small portion of the area, the annual estimated requirements for grass-seed works out to 8,000-10,000 quintals per hectare.

The seed production of forage crops is considered secondary in importance, because the economic product if the vegetative growth which is cut for animal consumption before the seed matures. Thus the new and high-yielding forage crops and their varieties will not be popular with the farmers and the overall impact of the increased yields of fodder crops will not be adequate unless the forage seed of the right quality and in the right quantity is made available to the growers at the right time and in the right place and above all at a reasonable price which a farmer can afford to pay.

Agronomy for high seed yields.

Like other cash crops, the forage crops show a good response to higher levels of nutrient supply for a higher out-turn of seed both in the case of cultivated and pasture species.

(a) Effect of nitrogenous fertilizers.   All the tropical and subtropical grasses show a linear response for seed production to the application of nitrogen. In Cenchrus ciliaris, the soil application of 670 kg of N per ha increased the seed yield from 8 to 500 kg per ha in Australia. Similarly, seed yield of the order of 20-60 kg per ha were obtained in the case of para (Brachiara mutica with 240 kg of N per ha. in Golden Timothy (Setaria sphacelata, 70 to 120 kg per ha of seed was obtained with 330 kg of N per ha. Likewise in India, the application of 40 kg of N per ha in two split applications during the monsoon increase the seed yields from 17 to 30 kg per ha in the case of C. ciliaris, 23 to 143 kg per ha in the case of C. setigerus and 70 to 239 kg per ha in the case of moshi (Iseilema laxum).

(b) Effect of phosphatic fertilizers.   Phosphatic fertilizers have a greater tendency to affect the fodder and seed yield, especially in the case of leguminous crops. Foliar spraying with 4 per cent phosphoric acid (40 kg of P₂O₅/ha) in the case of berseem, 15 days after the third cut in February resulted in 50 per cent increase in seed yield over that from the control. Similarly, in cowpea (Vigna sinensis) three split foliar sprays of 2 per cent phosphoric acid (25 kg of P₂O₅/ha) starting from the first flush of flowering and at intervals of 3-5 days, coupled with 50 kg of P₂O₅ per ha as soil application at the time of sowing in July, increased the seed yield by 30 per cent.

(c) Rational use of irrigation.   Seed-setting in the case of cash crops and forage crops is influenced by the available soil moisture at the critical periods of plant growth, i.e. flowering and anthesis. Taking advantage of this fact, water can be economized greatly and made available for other crops. Thus in the case of berseem, the application of two irrigations at 30 and 45 days after the third cutting resulted in a slightly higher seed yield than with four irrigations given at the recommended 15-day intervals, starting from the third cut. Likewise, the seed production in Kent oats, with two irrigations (after the crop establishment at 20 and 95 days growth) was of the same order as with five irrigations applied at 20, 45, 70, 95 and 115 days of growth.

Physiological approach to seed yield

The forage crops because of their excessive vegetative growth fail to produce sufficient seed for further multiplication on an appreciable scale. Some of the growth-regulators play an important role in increasing the seed yields. Foliar spraying with Cycocel (CCC), a growth-retardant, has been found to enhance seed production in the case of oats and jowar ('M.P. chari'). Spraying with CCC at the rate of 8.5 kg active ingredient per hectare at about 45 days' growth in the case of 'M.P. chari' and 2.0 kg of active ingredient per hectare just before the elongation stage in the case of 'Kent' oats increased the seed yield from 6.3 to 15.4 quintals per hectare in the case of 'M.P. chari' and from 11.8 to 27 q per hectare in the case of 'Kent' oats.

Similarly, a composite spray of micronutrients (Cu, Zn, Mo, B and Mn) in the form of zinc sulphate, manganese sulphate, and iron sulphate (each 100 ppm) and borax and sodium molybdate (each 10 ppm) at the rate of 700 liters per ha resulted in 30-50 per cent increase in seed yield in the case of berseem.

Flower abscission in the case of crops such as lucerne, berseem, cowpea, velvet bean, field bean, etc. is very common, but the growth-regulators when applied in low concentrations have a tendency to check abscission and produce more flower-bud primordia, resulting in a good seed-set per fruiting pod and a higher number of pods per plant. Thus the spraying of B-nine and CCC (each at 500 ppm) and Phosfon (100 ppm) in the case of cowpea, lucerne and berseem increased the seed yield by 60-90 per cent.

Role of external agencies

Other extraneous factors, such as the optimum population of efficient insect-pollinators in the case of cross-pollinated crops, such as lucerne and berseem, play a very significant role in seed production. It has been observed that temperate clovers, i.e. white and alike clovers, can be pollinated by all kinds of bees, but bumblebees work much faster in red clover than the hardy bees. The efficiency in pollinating the flowers of lucerne also varies. It has been observed that the honey-bees do not trip the flowers as efficiently as some of the other insect-pollinators, such as Ceratina binghami and Megachile flavipes.

In the case of legumes with a trailing growth habit, namely cowpea, velvet bean, field bean, Siratro, Clitoria ternatea, Atylosia, etc., the seed-setting and pod development is poor because of the competition for light, since the pods after development get buried in the vegetative mass. Thus the staking of the plants or making them climb on the fences and other suitable structures increases the pod- and seed-set two to three times in the case of field bean, velvet bean, siratro and cowpea.

Whom to contact to obtain forage seeds

For your requirements of seed or planting material of the fodder and pasture species, the following organizations may be contacted :
1. Director, Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh.
2. Director, Central Arid Zone Research Institute, Jodhpur, Rajasthan.
3. Director, National Dairy Research Institute, Karnal, Haryana.
4. Director of Regional Station of Forage Production and Demonstation of the following states

(i) Suratgarh, Rajasthan
(ii) P.O. Textile mills, Hissar, Haryana
(iii) Dam road, Surat, Gujarat
(iv) Jammu and Kashmir
(v) Rajendra Nagar Agricultural University, Hyderabad, Andhra Pradesh
(vi) Alamadhi, via Redhills, Tamil Nadu
(vii) Kalyani, West Bengal