lo Sept., 1908.] Potato Experimental Fields, Y^o-j-i,. 565 



by immature or green seed is that obtained by lifting the tubers before 

 they have matured and while the plant is still in full vigour. This, it 

 is well known, is contrary to the general opinion of growers, even at the 

 present day, for if the question of what condition tubers intended for 

 seed should be in when lifted be asked the majority of growers would 

 say: "Perfectly ripe and well matured," yet all the experiments in 

 Great Britain go to prove- the contrary. 



The tests of last season were repeated on a larger scale in the 1907-8 

 plots. A parcel of Up-to-date seed was lifted in a peifectly green con- 

 dition, and divided into four sets, two in field culture and two in garden 

 culture; also a parcel of Vermont Gold Coin was dug in a very green 

 condition, being so soft in the skin that it was impossible to gather them 

 without injury. They were allowed to lie on the ground covered with 

 the haulms for a month, when they Avere quite green and hardened by 

 exposure. This parcel was treated under garden conditions and was 

 entirely in favour of immature seed. The preceding tables show what 

 each parcel yielded. The market value of each crop of Up-to-date, on 

 the basis of 80s. per ton for table seed and 30s. per ton for small tubers, 

 is also given. 



From the above it will be seen that the green seed has scored in every 

 instance ; also, that green seed at Newlyn produced the smallest quantity 

 of unmarketable tubers and the reverse at Romsey, but in each of the 

 garden tests the immature seed produced the least unmarketable. The re- 

 turns from Vermont Gold Coin were as. follow : 42 sets each planted ; 

 one set in each lot unused, leaving 41 plants. 



4.1 Plants, Green. — 20 lbs. very fine table tubers. 



2 lbs. good seed tubers. 



\\ lbs. small tubers. 

 4-1 Plants, Ripe. — 9 lbs. medium table tubers. 



5 li>s. inferior seed tubers. 



2 lbs. small tubers. 



It must be stated that the garden test of Up-to-date was spoilt through 

 having waste water from the house run down beside the drill of ripe seed 

 by mistake. It was not intended to give them any assistance in the way 

 of irrigation. 



Change of Seed. 



In dealing with the varieties a number of tests were carried out to 

 ascertain the effect on the productiveness of a variety by the change of 

 seed from one district to another. So far the results have been against 

 the theory that change of seed improves the yield. That it is the reverse, 

 at least for the first season, is proved by the last two seasons' operations, 

 especially with the varieties of the Brown's River habit. 



It has been the practice in planting the plots to obtain a parcel of 

 locally grown seed which has been planted beside the same variety from 

 another district. In every instance the local seed has given the heaviest 

 gross return in spite of the standard of quality being in some cases very 

 low. The most striking instance of this was afforded by a parcel of 

 locally grown seed in the Trentham plot. Here it gave a gross yield 

 of 4 tons 19 cwt. with only 14 cwt. per acre of marketable tubers, whilst 

 the seed introduced from Mr. Park's plot at Romsev only returned 

 3 tons 16 cwt. gross with 2 tons 5 cwt. marketable. This was also the 

 case in Mr. Beale's plot at Kinglake. 



