and Magazine of the Ceylon Agricultural Society. 



275 



per cent, of the seed-producing healthy plants. 

 In planting cover plants on steep land it is im- 

 perative that the lines should follow the contour 

 of the land ; when they are made to run up and 

 down the hillside the seed will be washed down 

 with the loosened earth. This result in the 

 seeds being massed in one place, and the young 

 plants growing closely together in clumps at the 

 foot of the lines. Th<B use of cover plants in 

 place of clean weeding is now, after three years' 

 constant advocacy, very generally considered 

 as an economical and practical practice, which 

 1 have no doubt will greatly increase when 

 the benefit to the rubber aud the saving in ex- 

 pense have been proved on a large number of 

 estates. The relative advantages of various 

 plants as "cover plants" for rubber clearings is 

 an important question to decide before procee- 

 ding to lay down fields with one or other. Legu- 

 minous plants possess the property of increas- 

 ing the amount of available nitrogen in the soil 

 by means of bacteria living in their roots which 

 obtain nitrogen from the air, and in this respect 

 should be preferred to other plants. The 



CHIEF THING TO CONSIDER IN LAYING DOWN A 

 COVER PLANT 



is rapidity and cheapness in thoroughly estab- 

 lishing it, and if a plant is found to quickly 

 take possession of the soil and cover it to the 

 exclusion of all others, the fact of its not being 

 leguminous should not weigh against it. The 

 ideal plant for the purpose of protecting 

 rubber land and eliminating or reducing very 

 considerably the weeding bill is a plant which 

 grows not more than a foot to 18 inches high, 

 is permanent or persistent for three or four 

 years, producing shade over the ground, gro- 

 wing so luxuriantly as to exclude weeds with- 

 out forming a thick turf, is leguminous, has 

 no thorns or spikes to interfere with coolies 

 walking, has no leaves, fruit, or flower which 

 will attract vermin or other animals. None of 

 the plants at present in use, or being tried in the 

 experimental plots of the Agricultural Depart- 

 ment, fulfil absolutely all these requirements, 

 and it is probable that a plant will yet be 

 found better than any at present tried. The 

 conditions on different estates in Malaya do 

 not vary very greatly, but the differences are 

 sufficient to make some places specially favour- 

 able to one cover plant and other places to 

 other plants. In different districts on sloping 

 and fiat land with different soils and some es- 

 tates it is found that in some passion flower 

 will thrive and rapidly cover the land where 

 the sensitive plant or crotalaria do not grow 

 vigorously. On other places the crotalaria or 

 sensitive plant may do much better than 

 passion flower. 



It is easy to decide as to the most suitable 

 plant by planting one or two trial plots. The 



FOLLOWING PLANTS ALL HAVE ADVANTAGES 

 IN DIFFERENT WAYS, 



and if any one of them can be made to 

 entirely cover the ground in a short time, say 

 four or five months, its acquisition will be a great 

 gain to the estate in improving the growth of 

 the rubber and in reducing the wages bill. 



Abrus precalorius, a native of India, where it 

 is used for covor, is logumiuous with a froo 



creeping habit ; it grows about one foot above 

 the ground and the branches from one plant will 

 spread to 15 or 20 feet from the main stem. The 

 pods contain 6 or 8 seeds. The seeds are bright 

 vermilion, about the size of buckshot, with a 

 small black mark at one end ; they are used as 

 the carat or standard weight for precious stones 

 and metal in India. 



Passiflora fostida (passion flower creeper), a 

 creeping non-leguminous plant having purple 

 flowers and yellow fruits about the size of a 

 walnut, grows very freely on nearly all soils and 

 smothers many other plants of a less vigorous 

 habit. This creeper never gets more than about 

 nine inches to a foot high, and very quickly 

 covers the ground. It has to be kept from 

 twinning round young rubber plants, but as 

 it is very soft this can be done at extremely 

 small cost. It is a native plant and common 

 all over the Peninsula. 



Crotalaria striata and other specdos of the 

 same genus, Crotolaria incana, are leguminous 

 plants, possessing usually very numerous and 

 large bacterial nodules, and growmg freely, 

 when not cut, to 7 or 8 feet high. It has a 

 yellow flower and a light green leaf, and affords 

 a good cover if not allowed to grow high and 

 scraggy. It should be kept cut to a height of 

 about 2 feet 6 inches. The cutting is not a 

 costly process as it is only necessary to slash 

 over the tops, leaving the cut part to remain as 

 a mulch on the soil, The seed is obtainable 

 in almost any quantity as a large acreage is 

 already planted. 



Tephrosia purpurea and T. Candida, are both 

 vetch -like leguminous plants which grow freely 

 on almost any soil, and give perhaps a better 

 cover than crotalaria. They must, however, be 

 slashed over at a height of 2-3 feet, and not 

 allowed to run up; otherwise the light, and with 

 it the weeds, will gain an .entrance. 



Mimosa pudica, the "sensitive plant," a legu- 

 minous plant with red spherical flower heads 

 and spiny fruits, is in many ways the most suit- 

 able plant as yet tried for cover. The chief 

 reason which makes it disliked by planters is 

 the presence of thorns on its stems which are 

 unpleasant to coolies walking through it. 



The habit of this plant of shutting its leaves 

 in heavy rain and at night is an advantage as 

 no rain is lost and dew falls on the ground. 

 It never grows more than about two feet high ; 

 it persists and makes a dense cover over the 

 ground when the leaves are not shut— i.e., when 

 the sun i3 shining and tho plant is not dis- 

 turbed. It is, though a native of S. America, 

 common in all the planting districts and 

 one of the first plants to take possession, and 

 keep possession, of the roadsides. In addi- 

 tion to these plants I have recently been 

 shown a creeping leguminous plant which was 

 found by Mr. H. F. Browell of Damansara 

 estate. It is a species of Vigna, having dark 

 green leaves and making a dense cover which 

 refuses to allow any weeds to exist. I have 

 seen a patch of about half-an-acre on Damansara 

 estate, and there it appears to be the best plant 

 for the purpose of cover that has been used in 

 tho Federated Malay States, 



